1. Field of the Invention
The present invention relates to a process for forming an oil-soluble polyaniline-grafted polymers useful as electrically conducting polymers in electrical applications.
2. Discussion of Background
Polyaniline is one of the oldest polymers known, and has been prepared in the form of emeraldine hydrochloride by oxidizing an aqueous hydrochloric acid solution of aniline with ammonium peroxy disulfate at ambient temperature. Polyaniline is a cheap, highly electrically conducted polymer, but is processable with difficulty in its powder form. Conventionally, making such conjugated conducting polymers oil-soluble and processible has been a very difficult problem.
S. Li et al., Synth. Met. 20(2 ), 141-9 (1987) discloses the graft polymerization of polyaniline with polyaminostyrene to form polyaniline soluble in common organic solvents (DMF and DMSO, and slightly soluble in methanol and trichloromethane). This procedure involved the nitration of polystyrene (of 120,000 molecular weight) with either fuming nitric acid or a chloroform solution of 100% nitric acid and acetic anhydride. The resulting polynitrostyrene was hydrogenated with phenylhydrazine under nitrogen to form the polyaminostyreneo.
S. Li, "Synthesis and Characterization of Soluble Polyaniline, "Syn. Met. 29 (E329-E336) (1989) reports three general synthetic routes for the solubilization of polyaniline in DMF and DMSO. The experimental synthesis employed either formation of block polyaniline (employing either para-aminobenzenesulfonylchloride/poly (ethylene glycol ) reaction products or para-aminobenzoy. chloride/poly(ethylene glycol) reaction products, and the preparation of graft polyanilines by polymerization of aniline on polyaminostyrene, polyacrylamides or polyepichlorohydrin.
S. P. Armes et al., "The Synthesis of Poiymeric Surfactants for the Preparation of Sterically-Stabilized Polyaniline Colloids, "Polym. Mater. Sci. Eng., 60, 751-753 (1989) discloses copolymerization of 2- or 4-vinyl pyridine with para-aminostyrene.
T. Kobayashi et al. , "Polyaniline Film-Coated Electrodes as Electrochromic Display Devices," J. ElectroanaL, Chem. 161, 419-423 (1984) discloses evaluations of the electrochromic properties of polyaniline films.
A. G. MacDiarmid et al . , "`Polyaniline`: Interconversion of Metallic and Insulating Forms," Mol. Cryst. Lig. Cryst., 121, 173-180 (1985) describes the synthesis of polyaniline powder and the conversion of this material to various insulating and metallic forms by acid/base and oxidation/reduction mechanisms.
Y. Cao et al. , "Spectroscopic and Electrical Characterization of Some Aniline Oligomers and Polyaniline, "Syn. Met. 16, 305-315 (1986) describes the preparation of aniline oligomers and polyaniline, proton-doped derivatives.
W. Huang et al., "Polyaniline, a Novel Conducting Polymer, "J.Chem. Soc., Faraday Trans 1, 82, 2385-2400 (1986) discloses the chemical synthesis of polyaniline and electrochemical synthesis of polyaniline from aniline.
F. L. Lu et al. , "Phenyl-Capped Octaaniline (COA): An Excellent Model for Polyaniline," JACS 1.08, 8311-8313 (1986) discloses the preparation of a mono-dispersed polyaniline of molecular weight of 806 and its conversion to a partially oxidized form.
F . Wudl et al . , "Poly (p-phenyleneamine): Synthesis and Comparison to Polyaniline," JACS 1.09, 3677-3684 (1987) discloses the preparation of small polyaniline oligomers by a double condensation of para-phenyl amino-substituted anilines with diethyl succinoyl succinate and the preparation of poly(p-phenaline amine) by the reaction of succino succinic acid ( 2,5-dioxo-1,4 -cyclohexane dicarboxylic acid) and p-phenyl inediamine.
A. G. MacDiarmid et al. , "The Polyanilines: Processing, Molecular Weight, Oxidation State and Derivatives, "Polymer Pre-prints 30, 147-48 (1989); M Angelopoulos et al. "Polyaniline: Solutions, Films and Oxidation State, "Mol. Cryst. Lig. Cryst 160, 151-163 (1988); A. Andreatta et al., "Electrically-Conducted Fibers of Polyaniline Spun From Solutions in Concentrated Sulfuric Acid, " Syn. Met. 26, 383-389 (1988); A Ray et al , "Polyaniline: Doping, Structure and Derivatives," Synth. Met 29, 141-150 (1989); S. P. Armes et al , Colloidal Dispersions of Polyaniline, "J. Chem. Soc., Chem. Commun. 88-89 (1989) also relate to preparation of polyaniline.
Y. Wei et al., "Synthesis and Electrochemistry of Alkyl Ring-Substituted Polyanilines, "J. Phys. Chem. 93, 495-499 (1989) discloses the synthesis of poly(o-toluidine), poly(m-toluidine) and poly(o-ethylaniline), by chemical and electrochemical syntheses.
S. K. Manohar et al., "N-Substituted Derivatives of Polyaniline, "Syn. Met 29, 349-56 (1989) discloses the preparation of N-methylated polyaniline.
U.S. Pat. No. 4,604,427 relates to forming electrically conducting polymer blends by impregnating a pre-formed host polymer with a cyclic monomer such as aniline and then exposing the mixture with a chemical oxidant to form the conductive polymer reaction product within the surface layer of the host polymer.
Canadian Patent 806,736 relates to an antioxidant for hydrocarbon-type rubber which is in the form of an aromatic polymer having repeating units which consist of an NH-group attached to a difunctional aromatic group prepared by reacting either hydroquinone or para-benzoquinone with various aromatic diamines, such as para-phenylene diamine and 2,7-diamino naphthylene (page 4). The antioxidant activity of exemplary polymers were demonstrated in ethylene-propylene copolymer rubber vulcanisate (pages 7-8).
European Patent Publication 314,311 relates to the preparation of conducting articles by (a) forming a gel of a carrier polymer in a compatible solvent, (b) polymerizing a selected monomer within the gel, and (c) doping the article so provided. Disclosed carrier polymers include high molecular weight (M.W. &gt;100,000) flexible chain polymers, such as polyethylene, isostatic polypropylene, poly(ethylene oxide) and polystyrene, and lower molecular weight polymers (10,000-100,000) having "rigid-rod" molecules, such as aramid polymers, aromatic polyesters, PBT and PBI. The polymerization step (b) can include oxidative-coupling polymerization empioying aniline. The polymerization step results in the formation, within the carrier polymer, of a normally intractable polymeric material derived from the selected monomer.
European Patent Publication 314,845 discloses graft copolymers characterized by oil-soluble substantially linear, carbon-carbon backbone polymer having graft polymerized thereon units derived from RNH.sub.2 monomer, wherein R is a hydrocarbon containing a polymerizable ethylenically unsaturated double bond. Illustrated amine monomers include p-aminostyrene and p-(aminomethyl) styrene.
Polymers prepared from alpha-olefins using Ziegler catalysts have found acceptance for use in a wide range of applications including elastomers, fibers and films. Inasmuch as the polymers are essentially nonpolar, however, they have a characteristic inertness which makes them difficult to surface treat, for example, by dyeing or metallizing techniques. Additionally, they are limited in the amount of additives, such as stabilizers and plasticizers which they can accommodate without "blooming". Similar limitations are found in the rubbery copolymers and terpolymers produced from alpha-olefins.
In an attempt to overcome these disadvantages, efforts have been made to introduce polar functional groups into such polyolefins, both homo and copolymers. Previous efforts in this direction have included both the direct incorporation of functionalized monomers during the polymerization process as well as post-polymerization functionalization of polymers.
Efforts have been made to incorporate polar monomers directly into the polymer using various techniques. U.S. Pat. No. 3,492,277 discloses a method for forming a complex of a polar monomer containing a labile hydrogen, as in --NH.sub.2 , --COOH, or --OH, by contacting the polar monomer in an inert hydrocarbon solvent with an organoaluminum compound at a molar ratio of polar monomer to organo-aluminum compound of from 1:1 to 1:3, and then heating the solution to between 60.degree. and 150.degree. C. The organic aluminum compounds disclosed have the general formulas AlR.sub.1 R.sub.2 R.sub.3 or AlR.sub.1 R.sub.2 X' wherein R.sub.1, R.sub.2 and R.sub.3 are the same or different alkyl or aryl radicals and X' is either chlorine or bromine. The method disclosed is alleged to be useful with a wide range of monomers including those having polar groups such as --COOR', --CHO, --SH and --SO.sub.3 H. The polar monomers have the general formula: ##STR1## wherein n is an integer greater than 2, R is hydrogen, an alkyl or aryl radical, and Z is the polar moiety. Z can also be an aromatic nucleus bearing such moieties. Although R.sub.1, R.sub.2 and R.sub.3 are generally described as being the same or different aryl or alkyl radicals, this patent does not disclose that non-halogenated organoaluminum compounds affect the results achieved and otherwise disclose and illustrate the procedure by way of examples wherein a halogenated organoaluminum compound is used.
Reaction of the organoaluminum compound with the polar monomer results in a polar monomer reaction product complex, e.g. 5-hydroxy-1-pentene and diethyl aluminum chloride ##STR2## with the elimination of an alkyl or aryl radical from the organoaluminum compound. The complex can then be combined with alpha-olefin and Ziegler catalyst (titanium trichloride) for the polymerization. The polymerization is carried out at about 60.degree. C. to about 100.degree. C. The ratio of the preferred aluminum compound, diethylaluminum chloride, to titanium trichloride is 10:1 to 1:1.
U.S. Pat. No. 4,423,196 discloses a method of incorporating acyclic polar monomers into an alpha-olefin copolymer using an aluminum compound of the formula AlR.sub.n X'.sub.(3-n) wherein R is a C.sub.1 -C.sub.18 alkyl group, X' is halogen and 0&lt;n&gt;3. The polar monomer is contacted at room temperature with one mole of organoaluminum compound, and then allowed to react for 1 hour at 70.degree. C. Polymerization is carried out using TiCl.sub.3 as the Ziegler catalyst, the ratio of organoaluminum to TiCl.sub.3 is 1:1 to 100:1. Polymerization is carried out at about 20.degree. C. to 100.degree. C. and preferably about 60.degree. C. to 90.degree. C. Illustrative of the polar monomers disclosed are eugenol and undec-1-enoic acid. The disclosure of EPO Patent Application No. 14,822 is similar in scope, but also discloses ethylene as a compound considered to be an alpha-olefin.
Matsumura, K. and Fukumoto, O., J. Pol. Sci., 9 471-483 (1971) discloses the copolymerization of propylene using a Ziegler-Natta type catalyst (equimolar quantities of TiCl.sub.3 and triethyl aluminum) in the presence of ethylchloro-aluminum acrylate, which was formed by the reaction of acrylic acid with diethyl aluminum chloride under N.sub.2 at room temperature with cooling.
An article by Spevak, L. L.; Ivanochev, S. S.; et al entitled, "Copolymerization of Ethylene with Acrylic Acid and Its Derivatives Using the Catalyst System Al(C.sub.2 H.sub.5).sub.2 Cl-VO(OC.sub.2 H.sub.5).sub.3 "(Sci.-Ind. Enterp. "Plastpolim" , Leningrad, USSR) Plaste Kautsch, , 29 (1) , 12-15, 1982, discloses the preparation of ethylene/acrylic acid copolymers. An excess of organo aluminum compound is utilized both to complex the acrylic acid and to act as a cocatalyst for the AlEt.sub.2 Cl-VO(OEt).sub.3 polymerization catalyst system. Complexing of the acrylic acid is accomplished in situ during the polymerization process.
U.S. Pat. No. 3,796,687 discloses the preparation of ethylene-alpha-olefin-nonconjugated diene terpolymers using as a fourth monomer a polar compound of the formula: CH.sub.2 =CH--(CH.sub.2).sub.n -Y wherein n is an integer from 0 to 20 and Y is a functional group which can be ##STR3## and --SO.sub.2 Cl wherein R is H, alkyl, aryl or cycloalkyl containing 1 to 18 carbon atoms and R.sub.1 is either --R or --OR. Other polar compounds disclosed include bridged ring compounds (substituted norbornene) and substituted aromatic compounds. The substituents include those described above as well as alcohols. The polymerization catalyst comprises a vanadium compound and an organoaluminum cocatalyst in conjunction with a halogenated compound (e.g. , hexachloropropylene) as catalyst reactivator. The ratio of aluminum compound to vanadium compound is at least 2:1 preferably 10:1. The polymerization is conducted by dissolving ethylene and a comonomer alpha-olefin in the reaction solvent, the alkylaluminum compound is then added, followed by addition of the unsaturated functional monomer and any diene, then any catalyst reactivator, and finally the the vanadium compound.
U.S. Pat. Nos. 3,884,888, 3,901,860, and 4,017,669 are related to U.S. Pat. No. 3,796,687 and have substantially the same disclosures. U.S. Pat. No. 3,884,888 is directed to EPDM which contains as a fourth monomer, a bridged ring compound, e.g., norbornene substituted with a group defined as being --(CH.sub.2).sub.n -Z where n is 0 to 20 and Z is ##STR4##
U.S. Pat. No. 3,901,860 is directed toward EPDM wherein the substituent is similar to that of U.S. Pat. No. 3,884,888 except that Z is COOH. U.S. Pat. No. 4,017,669 claims as the fourth monomer the same bridged ring structure of U.S. Pat. No. 3,884,888 and U.S. Pat. No. 3,901,860 except that the substituent is --(CH.sub.2).sub.n -COOR, wherein n is 0-20 and R can be alkyl, aryl, or cycloalkyl.
Japanese Patent No. JA 7337756-R discloses the copolymerization of an alpha-olefin with an unsaturated carboxylic acid of the formula CH.sub.2 .dbd.CH--(CH.sub.2).sub.n -COOH. The polymerization catalyst is a halide of Ti or V and an organoaluminum compound. The organoaluminum compound can be of the formula R.sub.3 Al, R.sub.2 AlX, RAlX.sub.2 R.sub.2 AlOR', RAl(OR') X and R.sub.3 Al.sub.2 X.sub.3 where R and R' are alkyl or aryl and X is halogen. The polymerization is effected at 0.degree.-130.degree. C. and 0-50 atmospheres There is no prereaction of the aluminum compound with the carboxylic acid compound.
U.S. Pat. No. 3,761,458 discloses a process applicable to alpha-olefin containing polar monomers in which the polar groups are separated from the alpha-olefin by two or more carbon atoms. The polar monomer can contain more than one polar group. The polar group can be one of the amino, cyano, phosphine, (hydrocarb)oxy, metal-metalloid-containing groups, as well as metal salts of acid groups such as --COOH, --SO.sub.3 H, --PO(OR)OH, carboxyl groups, or hydrocarbyl sulfide groups. An essential component of the catalyst system is the halide or alkoxyhalide of a transition metal e.g., TiCl.sub.3. The preferred cocatalyst is an aluminum alkyl. Other catalysts include vanadium trichloride, zirconium tetrachloride etc. The aluminum compound has the formula AlR.sub.3 or RR'AlX wherein R is hydrocarbyl, R' is H or hydrocarbyl and X is halogen, H, alkoxy, aryloxy etc. All monomers and catalyst components are added to the reaction and there is no preference as to order of addition of the monomers. The preferred alkyl groups of the catalyst component is ethyl, but n-propyl, isopropyl, n-butyl, isobutyl, n-octyl or 2-ethyhexyl groups are taught as suitable.
U.S. Pat. No. 4,139,417 discloses amorphous copolymers of mono-olefins or of mono-olefins and non-conjugated dienes with unsaturated derivatives of iraides. The polymer comprises about 99.9 to 80 weight percent of non-polar units derived from at least two mono-olefins containing 2 to 18 carbon atoms, particularly ethylene and propylene, and optionally one more non-conjugated diene. In the preparation of the polymer the imide is complexed with a Lewis acid, e.g. alkylaluminum dihalides, aluminum trihalides, boron halides, nickel halides. It is indicated that the Lewis acid-imide complex has a higher stability than that of the reaction products which the non-saturated imide may form with components of the coordination catalyst system used for the copolymerization. The complex between the Lewis acid and the unsaturated imide may be formed before being introduced into the polymerization zone, by dissolving the imide and Lewis acid in an inert solvent maintained at -80.degree. C. to 80.degree. C. Catalyst systems which are disclosed as being particularly suitable for the preparation of the copolymers are formed by the association of an organoaluminum compound with titanium, vanadium, tungsten or zirconium derivatives e.g. halides or oxyhalides. The organoaluminum compound may have the formula EQU AlY.sub.n Cl.sub.(3-n)
wherein n is 1, 3/2, 2 or 3 and Y is a lower alkyl group, e.g., C.sub.2 -C.sub.6 alkyl the aluminum compound being associated with a titanium halide, vanadium halide or vanadium oxyhal ide.
Japanese Patent Application No. 188996/1982 (Laid Open No. 80413/1984; May 9, 1984) discloses a process for preparing a copolymer of an olefin and a polar vinyl monomer which comprises copolymerizing an olefin with a complex of the polar vinyl monomer and a Lewis acid. The amount of Lewis acid is in excess of an equimolar amount of polar monomer. The Lewis acid is represented by the general formula R.sub.m MX.sub.n wherein R is a hydrocarbyl group; M is B, Al or Sn; X is halogen, and n is greater than zero. Illustrative of the Lewis acid are ethylaluminum dichloride, aluminum chloride, boron trichloride and tin chloride. The polar vinyl monomer is an ester of an unsaturated alcohol and an organic acid. The catalyst component used in the copolymerization process comprises magnesium, titanium, halogen and an electron donor. It is prepared by heating or copulverizing a combination of magnesium or a magnesium compound, a titanium compound and an electron donor.
Japanese Patent Application No. 152767/1982 (Laid Open No. 43003/1984, 5/19/84) is similar in scope to Japanese Application No. 188997/1982. The catalyst of Japanese Patent Application No. 152767/1982 however, comprises a reduced titanium tetrachloride with an organoaluminum compound activated by an electron donor such as ether, ester, amine and/or a halogen containing compound. Illustrative of halogen containing compounds are the tetrachlorides of titanium, silicon and tin; hydrogen halide, halogens and halogenated hydrocarbon.
European Patent Application No. 295,076 relates to polyolefins incorporating carboxyl, hydroxyl, thio, amino, carbonyl and imino functional groups, masked functional group-containing monomers and methods for preparing the same, by reacting the functional group containing monomers with non-halogenated organometallic compounds to form masked, functional-group containing monomers, and polymerizing polymer chain monomers with the masked monomers to produce a polymer chain.